SUPPLEMENTARY INFORMATION Schedule of Pass Through Costs (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Cost of Reimbursable Expense	$ 14	$ 10

Cost associated with reimbursable income. This occurs when a services entity incurs expenses on behalf of the client and passes through the cost of reimbursable expenses to a client.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Name:	us-gaap_CostOfReimbursableExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration